The present invention relates to a heat exchanger for cooling a hot gas that contains solid particles.
A heat exchanger of this type is known from EP 0 567 674 B1, and serves for cooling synthetic gas produced in a coal gasification unit. With the known heat exchanger, the tube plate on the gas inlet side is covered with a ceramic layer to protect against erosion and high temperature corrosion. The ceramic layer is comprised of individual ceramic sleeves that are disposed next to one another and that in the upper part have right-angled outer edges that abut one another, and in the lower part have an opening, which extend into the heat exchanger tubes. Below the sleeves, on the tube plate, the weld seam and the tube inlets, is a protective layer comprised of a metallic adhesive layer and a ceramic layer. This protective layer becomes operational if one or more of the sleeves are destroyed.
It is an object of the present invention to simplify a heat exchanger of the aforementioned general type, and to provide more effective erosion protection.